Simulation study on the mode cutoff frequency in large mode area photonic crystal fibers

The number of transverse modes and the field distribution in large-mode area photonic crystal fibers (PCFs) are simulated. Through adjusting the PCF structure parameters, the mode properties can be controlled to meet the actual needs. The single mode cutoff in the triangular or square lattice large mode area PCFs is analyzed. The single mode cutoff frequency is obtained, and the V parameter and the normalized cutoff frequency V* are redefined. The result shows that, by increasing the number of the missing central air holes, V* is more and more close to 2.405 for triangular lattice PCF, and π/2 for square lattice PCF.